A senior official in China demanded last week that foreign embassies stop releasing air pollution data after a U.S.-run Twitter feed directly contradicted official Chinese readings over several months. Many residents of smog-coated cities dismiss official readings of "slight" pollution, and since the state tightened monitoring standards in January, the embassy's measured air pollution level is often at odds with China's own data. Though China did not specifically mention the U.S. embassy, the nation's experts have previously criticized the measurements as "unscientific," and an official said that the readings were illegal. "According to the Vienna Convention on Diplomatic Relations . . . foreign diplomats are required to respect and follow local laws and cannot interfere in internal affairs," said Deputy Environment Minister Wu Xiaoqing. Wu complained that data from a lone source does not represent broader air quality in China, a fact the U.S. embassy acknowledges on its website. The embassy in Beijing began tracking and releasing data in 2008, followed by consulates in Guangzhou and Shanghai. A spokesman for the embassy wrote that the data "is a resource for the health of the consulate community, but is also available through our Twitter feed for American citizens who may find the data useful." In addition to outside monitoring by embassies, citizens in smog-plagued cities have begun taking independent air quality readings and posting the results on microblogging sites. Days with high smog levels now cause "PM2.5" to trend on Weibo, a Chinese site similar to Twitter. For the full story, see and Earlier: